SU454503A1 - The method of measuring the phase characteristics of the recorder - Google Patents

Description

one

The invention relates to phase-measuring technology and can be used to create devices for monitoring the quality of magnetic recording of electrical signals.

The known methods for measuring the phase characteristics of a tape recorder, based on the regeneration of a reference signal synchronous with a reproducible, have a low accuracy, and the measurement process itself is carried out in two stages.

The aim of the invention is to improve the measurement accuracy and simplify the measurement process.

This is achieved by recording a signal on the magnetic tape containing reference pulses and packages of measuring frequencies synchronous with them, and during reproduction the phase characteristic is determined by comparing the reproduced complex signal and the regenerated one synchronous with the reproduced signal.

The drawing shows a block diagram of a device measuring in accordance with the proposed method.

It contains a generator of reference pulses 1, recording mode switches 2 (A and B), a synchronous generator of measuring frequencies 3, the device under study 4, a sync generator 5 and a dual-beam oscilloscope 6.

The measurement process is as follows.

The signal from the output of generator 1 through a switch 2A is fed to a synchronous generator of measuring frequencies 3, and the signal from its output through a switch 2B enters the recording input of the device under study 4 and is reproduced.

The reproduced signal from the output of the device under study 4 is sent to the synchronizer separator 5, in which reference pulses are extracted and formed. Switches 2A and 2B are then moved to position b. The reference pulses from the output of sync selector 5 are fed to the input of synchronous generator 3. The signal from the output of generator 3 is iodized to one of the inputs of the oscilloscope 6. To the other input of the oscilloscope, a reproduced signal is output from the output of the device under study 4.

The oscilloscope is synchronized by reference pulses from the output of the sync selector 5. On the oscilloscope screen two images are taken. From the comparison of two signals, the phase shift is determined by the time of crossing the zero levels, which characterizes the group delay time, and when compared on other frequencies, the characteristic group delay time in the frequency range under study. When calculating the relative

phase shift group time zanazdyvapn on the first n.

the frequency is equal to zero.

Subject invention

A method of measuring the phase characteristic of a magnetic recorder, based on the regeneration of a reference signal, synchronized with reproducible, is about the same and with that.

in order to increase the accuracy and simplify the measurement process, they form a complex signal consisting of reference pulses and measurement frequency packets synchronous with them, record it on a magnetic tape, and the phase response is determined by comparing the reproduced complex signal and the regenerated one synchronous with the reproduced signal.